Spark plug



j/gggmi W. K. ANDERSEN SPARK PLUG Filed June 2, 1934 arch 17, 1936.

Patented Mar. 17, 1936 2,034,170

UNITE STATES PATENT OFFICE SPARK PLUG William K. Andersen, Brooklyn, N.Y.

Application June 2, 1934, Serial No. 728,749 14 Claims. (01. 123-169) Myinvention relates to spark plugs, and more partly in section of a sparkplug equipped with particularly to improvements in spark plugs of amodified form of auxiliary electrode and showthe type including a mainspark gap and an auxiling the latter in one position of adjustment iaryspark intensifying gap. thereof,

Broadly stated the primary object of my in- Figure 7 is a similarfragmentary view illusb. vention is to provide a spark plug withimproved trating the modified form of electrode in another means forforming or closing at will an auxiliary position of adjustment.

intensifying spark gap, the operation and condi- Figure 8 is a bottomplan View of a cap member tion of which may be readily observed at alltimes in which said modified electrode is mounted and and which can beoperated selectively only to F ur 9 s a p p iv v w f h mod fied 10 fullyopen or fully close the gap, so that when form of electrode. opened thegap shall be invariable from a prep fi y describing the illustratedembodidetermined proper length to prevent alt ration ment of theinvention reference character I desigin such a manner as to interferewith eflicient hates the y Shell 0 Ve 0f t e p u having operation of theplug, said means being capable a reduced lower end 2 externally threadedas at 3 -15 of quick and easy manipulation without th use for insertioninto the cylinder head of an engine, of tools to close or open theauxiliary gap, an internal shoulder 4 substantially midway of Morespecifically the principal object of my the sleeve, internal threads 5in t upper invention is to provide a spark plug equipped with and the1151-1341 heXegOnel portion 5 0 the app caa novel form of auxiliaryelectrode and mounting tien of a Wrench t0 the sleeve- 20 therefor, saidelectrode being movable relative to secured the Sleeve 1 is aCylindrical o a main electrode into gap forming and gap 1 of suitableinsulating material, having. a radial ing position, and tensioned formovement to the flange 3, t ia y midway of its ends. latter position sothat it is incapable of permaclamped between the aforesaid Shoulder 4and nently assuming an intermediate position, said a gland nut 9threaded into the pp end of 25 auidliary electrode having a partprojecting the sleeve, suitable gaskets I0 and l I being inlaterallyfrom said plug for manual manipulation telpesed between Said flange a heS ulde 4 of the electrode to a gap forming position and and gland H 9respectivelypp r n of said mounting and electrode being provided withthe Core 7 is provided With a d a al bo e cooperating interengagingparts for holding the l2 terminating a its wer end in a Shoulder I3 30auxiliary electrode in gap opening position. and open into l'eletivelySmaller t d d Other and subordinate objects, such as durabore M which intu p s into a s a l r bore bility, low cost of manufacture, andsimplicity of 15 p ng into t e eeve construction, will'presently appearand the nature EXtending through Said bores and I5 is of my improvementswill be clearly understood a main electrode l6 secured therein by m a Of35 when the following description and claims are an enlar te ate s endsthreadread in conjunction with the drawing accomed into the bore l4, andhaving a radial flange l8 panying and forming a part of thisspecification. bearing gainst a gasket 9 Seating in the Shoul- Referringto the. accompanying drawing in der 13. The usual grounding electrode 20is se- 40 which corresponding and like parts are designated cured in theshell I for cooperation with the lower 40 throughout the several viewsby the same referend of the electrode I6 to provide a main spark encecharacters, p-

Figure l is a view in vertical section of a spark Referring nowparticularly to the embodiment plug equipped according to my invention,of my invention illustrated in Figures 1 to 5 in- Figure 2 15afragmentary side elevation illuselusive, threaded into the upper end ofthe bore 45 trating an auxiliary electrode forming part of IE is acoupling sleeve 2! of conducting material, my invention, in aposition ofadjustment thereof, such as brass and having a flat externally Figure 3is a similar view illustrating the auxthreaded head 22 seating on theupper end of iliary electrode adjusted to another position, the core 7.A gasket, of insulating material may re 4 is a bottom plan view of a capmember, be interposed between the coupling member 2| 50 in which saidauxiliary electrode is mounted, toand flange l8 whereby said couplingmember gether with the electrode, serves as a lock nut preventingloosening of the Figure 5 is a perspective View of the auxiliary mainelectrode Hi from engine vibration or other electrode, causes.

Figure 6 is a view partly in side elevation and Surmounting the core 1is a cylindrical cap 55 member 23 internally threaded, as at 24, forengagement with the head 22 and of the requisite depth to provide asparking chamber 25 into which the upper end of the main electrode l6extends. The usual binding post 26, having a nut 21 thereon, projectsfrom the top of the cap member 2|.

Mounted in the cap member 2| in an internal circular groove 28 formedtherein by the threads 24 and the top of said member, is an auxiliaryelectrode 29. The auxiliary electrode 29 is formed preferably from asingle piece of resilient wire or other rod like material bent upon'itself to form a circular open loop 39 freely mounted in said groove 28,and subjacent diametrical sparking members 3| disposed side by side andtensioned to be normally urged downwardly, said members being of alength to extend laterally from the cap member 23 and terminatingexteriorly thereof in an eye member 3| for manual manipulation thereoffor a purpose presently seen. A bayonet slot 32 through which thesparking members 3| project, is formed in the side wall of the capmember and provides upper and lower detent notches 33 and 34,respectively, spaced apart circumferentially of said side wall anddesigned to seat said sparking members, as shown in Figures 2 and 3.Since the auxiliary electrode 29 is freely mounted in the groove 28 andthe sparking members 3| are yieldingly urged downwardly said members maybe lifted from either notch, as by means of the eye 3|, and saidelectrode 29 rotated to position said members 3| over the other notch toseat therein with a snap action when said eye is released. When seatedin the upper notch 33 said members 3| provide for an auxiliary spark gapbetween the same and the upper end of the main electrode l6 whereby thespark at the main gap is augmented or intensified in a manner wellunderstood and therefore not requiring explanation. On the other handwhen seated in the lower notch 34 said sparking members 3| are in directcontact with the upper end of the main electrode l6 and the auxiliaryspark gap is closed and eliminated. By virtue of the two sparkingmembers 3|, side by side, provision is made for jumping of the spark atvarious points according to fluctuations of the ignition current. Sightopenings 35 are provided in the side wall of the cap member 23 throughwhich the operation and condition of the auxiliary electrode may bereadily observed.

In the modification shown in Figures 6 to 9, inclusive, an auxiliaryelectrode is provided in the form of a cylindrical plunger 36 movable intheside wall of the cap member 23 radially of the upper end of the mainelectrode l6 and provided exteriorly of said cap member, with a headmember 31 for manual manipulation thereof. A resilient wire 38 is coiledaround the base of the binding post 26 and has a downturned detent end39 projecting through a suitable aperture 49 in the top of the capmember 2| and adapted to seat in either of a pair of concave circularnotches 4| and 42 arranged in said plunger so that the latter maybepulled outwardly, as in Figure 6, or pushed inwardly as in Figure 7,and yieldingly held in either position. In its outward position theinner end of the plunger 38 is spaced from the main electrode to providean auxiliary spark gap; in its inward position said gap is closed.

The foregoing auxiliary electrode 29 and cap member 2| are easilyassembled to provide a manufacturing unit which may be applied toexisting types of spark plugs. The wire electrode because of itsresilient character is securely interlocked with the groove 28 while atthe same time it may be easily rotated therein for the purpose describedand readily removed for replacement as desired. The auxiliary electrodemay be' quickly adjusted to close or form the auxiliary gap withoutdisturbing the connection to the binding post, and said cap provides forlocation of said post in the usual position. Said electrode and relatedparts ensure accurate adjustment of the auxiliary spark gap and therebypositively insure efiicient operation of the plug when used either as asingle or double gap type.

While a preferred embodiment and one modification thereof have beendescribed in the foregoing it is to be understood that right is hereinreserved to other changes and modifications falling fairly within thescope of the appended claims.

Having thus described the invention, what I claim is:

1. In a spark plug including a main electrode extending above the upperend thereof, a cap member mounted on the upper end of said plug andhaving a chamber into which said electrode extends, and an auxiliaryelectrode mounted in said cap member and including an elongate sparkingmember extending across the upper end of the main electrode andvertically movable into gap forming and closing positions, respectively.said cap member having a slot therein provided with a notch, saidsparking member projecting through said slot for manual manipulationthereof to said positions and having interlocking engagement with saidnotch in said gap forming positions.

2. In a spark plug including a main electrode extending above the upperend thereof, a cap member mounted on the upper end of said plug andhaving a chamber into which said electrode projects and a slot in theside wall thereof provided with notches, and an auxiliary electrodemounted in said cap member and comprising an elongate sparking memberextending across the upper end of said main electrode and through saidslot, said sparking member having lateral hinging movement to gapforming and closing positions, respectively, and being tensioned forinterlocking engagement with said notches in said gap forming position.

3. In a spark plug including a main electrode extending above the upperend thereof, a cylindrical cap member mounted on the upper end of saidplug and having a chamber into which said electrode extends and a slotin the side wall thereof provided with notches spaced circumferentiallyof said wall, and an auxiliary electrode mounted in said cap member andcomprising an elongate sparking member extending across the upper end ofsaid main electrode and through said slot, said sparking member beinglaterally movable to gap forming and closing positions, respectively,and laterally movable for engagement with said notches in saidpositions.

4. In a spark plug including a main electrode extending above the upperend thereof, a cylindrical cap member mounted on the upper end of saidplug and having a chamber into which said electrode extends and a slotin the side wall thereof provided with notches spaced at differentlevels and circumferentially of said wall,

and an auxiliary electrode comprising an elongate sparking membermounted in said cap mem ber to extend across the upper end of said mainelectrode and through said slot, said sparking member having verticalmovement to gap forming and closing positions, respectively, and rotarymovement for location relative to said notches in said differentpositions, and being tensioned for interlocking engagement with saidnotches.

5. In a spark plug including a main electrode extending above the upperend thereof, a cylindrical cap member mounted on the upper end of saidplug and having a chamber into which said electrode extends, ahorizontally disposed circular groove in said chamber and a slot in theside wall of said member provided with notches spaced circumferentiallyof said wall, and an auxiliary electrode comprising a circular loopdisposed in said groove, an integral elongate sparking member extendingdiametrically from said loop across the upper end of said main electrodeand through said slot, said sparking member having vertical movement onsaid loop to different positions to vary its relation to the upper endof said main electrode, and for interlocking engagement with saidnotches in said different positions, respectively, the auxiliaryelectrode being rotatable in said groove for location of the sparkingmember relative to said notches.

6. A manufacturing unit, for use with a spark plug and comprising acylindrical sleeve member closed at one end and having a binding postextending from said end, and a bayonet slot in the side wall thereof,and a single piece electrode comprising a circular open loop mounted insaid sleeve for rotation about the axis of the latter and terminating atone end in an elongate member extending diametrically across said loopand through said slot and having hinging movement on said loop.

'7. As an article of manufacture, for use with a spark plug, acylindrical sleeve member closed at one end and having an annularinternal groove adjacent said end and a bayonet slot formed in one sidewall, and a threaded post projecting from said closed end.

8. As an article of manufacture, a single piece electrode of rod-likeresilient material and comprising an open circular loop, and an elongatemember extending from one end of said loop diametrically across andbeyond the latter.

9. As an article of manufacture, a single piece electrode of rod-likeresilient material and comprising an open loop and an elongate memberextending from one end of said loop diametrically across and beyond thelatter said member being bent back upon itself to form an eye at the endof said member.

10. As an article of manufacture, a single piece electrode of rod-likeresilient material and comprising, an open circular loop and an elongatemember extending from one end of the loop diametrically across andbeyond said loop said member being bent back upon itself to form aterminal eye and a second elongate member parallel with and contiguouswith said first member.

11. A spark plug comprising a cylindrical core, having a series of axialcommunicating bores of successively smaller diameter from the upper endof said core, the upper and next succeeding bore having a shouldertherebetween, an electrode ex tending through said bores and core andhaving an enlargement intermediate its ends threaded into said nextsucceeding bore and terminating in a head adapted to seat against saidshoulder, a sleeve member of conducting material threaded into saidupper bore and projecting at its outer end from the same, an insulatinggasket interposed, between said sleeve and head, a chambered cap memberof conducting material threaded onto the projecting end of said sleeveand into which said electrode extends, and a second electrode in saidchamber for forming a spark gap at the upper end of said firstelectrode.

12. In a spark plug including a main electrode, an auxiliary electrodemovable relative to the main electrode to gap forming and closingpositions, respectively, and tensioned for movement to one of saidpositions, said plug embodying devices cooperating with said electrodetolock the same in either position with a snap action.

13. In a spark plug including a main electrode extending above the upperend of said plug, a cylindrical cap surmounting said plug and having achamber into which said electrode extends and an opening in the sidewall thereof, and an auxiliary electrode slidably mounted in said capmember and comprising a sparking member movable relative to said mainelectrode into gap forming and closing positions, respectively, andprojecting through said opening, and cooperating means on said electrodeand cap normally infiuencing said electrode in one direction or theother and locking the electrode in said positions.

14. In a spark plug including a main electrode and a main spark gap, anauxiliary electrode adjustable relative to the main electrode betweentwo fixed points for limiting its movement in opposite directions toclose and form an auxiliary spark gap, respectively, and being incapableof permanent adjustment between said two points, and said plug andauxiliary electrode embodying cooperating devices for locking theauxiliary electrode at one limit of its movement, whereby a spark gap offixed length is ensured.

WILLIAM K. ANDERSEN.

